/*
 * This file is part of libsidplayfp, a SID player engine.
 *
 * Copyright 2011-2013 Leandro Nini <drfiemost@users.sourceforge.net>
 * Copyright 2007-2010 Antti Lankila
 * Copyright 2001 Simon White
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#ifndef C64CIA_H
#define C64CIA_H

// The CIA emulations are very generic and here we need to effectively
// wire them into the computer (like adding a chip to a PCB).

#include "Banks/Bank.h"
#include "sidplayfp/c64/c64env.h"
#include "sidplayfp/sidendian.h"
#include "CIA/mos6526.h"

/**
 * CIA 1
 * Generates IRQs
 * located at $DC00-$DCFF
 */
class c64cia1: public MOS6526, public Bank
{
private:
    c64env &m_env;
    uint_least16_t last_ta;
    uint8_t lp;

protected:
    void interrupt(bool state)
    {
        m_env.interruptIRQ (state);
    }

    void portB()
    {
        const uint8_t lp = (prb | ~ddrb) & 0x10;
        if (lp != this->lp)
        {
            m_env.lightpen();
            this->lp = lp;
        }
    }

public:
    c64cia1(c64env *env) :
        MOS6526(&(env->context ())),
        m_env(*env) {}

    void poke(uint_least16_t address, uint8_t value)
    {
        write(endian_16lo8(address), value);

        // Save the value written to Timer A
        if (address == 0xDC04 || address == 0xDC05)
        {
            if (timerA.getTimer() != 0)
                last_ta = timerA.getTimer();
        }
    }

    uint8_t peek(uint_least16_t address)
    {
        return read(endian_16lo8(address));
    }

    void reset()
    {
        last_ta = 0;
        lp = 0x10;
        MOS6526::reset ();
    }

    uint_least16_t getTimerA() const { return last_ta; }
};

/**
 * CIA 2
 * Generates NMIs
 * located at $DD00-$DDFF
 */
class c64cia2: public MOS6526, public Bank
{
private:
    c64env &m_env;

protected:
    void interrupt(bool state)
    {
        if (state)
            m_env.interruptNMI ();
    }

public:
    c64cia2(c64env *env) :
        MOS6526(&(env->context ())),
        m_env(*env) {}

    void poke(uint_least16_t address, uint8_t value)
    {
        write(address, value);
    }

    uint8_t peek(uint_least16_t address)
    {
        return read(address);
    }
};

#endif // C64CIA_H
